Revert "remove the splash image as it requires too many dependencies to be worth it"

This reverts commit ddcd94e4ff.

gatsby-config.js

@@ -4,6 +4,7 @@ module.exports = {
   plugins: [
     `gatsby-plugin-react-helmet`,
     `gatsby-plugin-emotion`,
+    `gatsby-plugin-image`,
     // create routes for client side routing
     // provide fonts from Google fonts
     // {
@@ -40,6 +41,7 @@ module.exports = {
         cache_busting_mode: 'none'
       },
     },
+    `gatsby-plugin-sharp`,
     {
       resolve: `gatsby-source-filesystem`,
       options: {
@@ -48,6 +50,7 @@ module.exports = {
       },
     },
     // parse data from /src/data as Javascrip objects
+    `gatsby-transformer-sharp`,
     `gatsby-transformer-json`,
     {
       resolve: `gatsby-source-filesystem`,